The C-3S13U-40 from Teledyne Microwave Solutions is a RF & Microwave Circulator with Frequency 3.7 to 4.2 GHz, Average Power Forward 50 W, Peak Power 1000 W, Insertion Loss 0.25 dB, Isolation 25 dB. Tags: Coaxial Circulator. More details for C-3S13U-40 can be seen below.